Clean and Sustainable Energy for San Pablo


Project Members:
Jason Kurian – Biochemistry major
Brittney Cooper – Landscape Architecture major
Trevor Hooper – Graphic Communications major
Steven Kinnear – Industrial Engineering major

Problem Statement:
hillside.jpgDue to a rough history with the local power company, San Pablo has resorted to using power from the power company without paying for their bill. Because of legal issues, the power company cannot stop providing the village with electricity but needless to say, the power company is not happy with San Pablo’s actions and threats have been thrown around as a result. There is a very real fear that killings over this matter will ensue if things remain as they are. San Pablo is reliant on the electricity they have been receiving over the years and need to find an alternative solution. Because San Pablo hasn’t had to worry about paying for their electricity, they have fallen into bad habits in respect to power usage. The biggest consumption of their electricity goes into lighting and the heating of water. This is mainly due to leaving the lights on when their not needed, using inefficient bulbs, and using inefficient technologies for heating their water.

Our goal is to educate the San Pablo community about the importance of being less wasteful with their energy. We also want to come up with a solution to provide San Pablo with a source of energy that can be renewable and maintained by the local community. Microhydro appears to be the most viable system considering the geography of San Pablo.


  • To have students draw connections between electricity use and the cost associated with it.
  • To teach students how micro-hydro systems work and how much electricity they can generate from it.
  • Lead students to discover that they can produce all the electricity for their village from a micro-hydro system.
  • Have students implement and practice ways to reduce their electricity use.
  • Demonstrate to students that becoming efficient in energy consumption will benefit them locally, while also benefiting the environment globally.

What has been done:
external image solar-panels-1.jpg

  • Solar Panels: Several solar panels have been installed in San Pablo. While the solar panels provide a clean source of energy, they are very expensive to buy and maintain. San Pablo would not be able to buy enough solar panels to provide enough energy for the entire village.
  • Hydropower: A previous Appropriate Technologies group tried designing a Power power_bucket.jpgBucket which operates on the same principles of micro-hydro and is made of affordable parts that are easily available at a hardware store. The idea seemed promising but, the power bucket was not able to produce enough electricity for it to be a viable solution.

Project Constraints:

  • Funding: The project needs to be easily affordable for all of the members of the village. It is important that this project does not incur too much debt. The curriculum would require funding to pay for the teachers and for any teaching aids such as power meters. The microhydro system would require funding to install and maintain the system. The estimated cost of the proposed microhydro system is explained further below.

  • Education: The inhabitants of San Pablo need to be educated in an effective, lasting, and progressive manner. Anything less would fail to make a noticeable and lasting effect on the community. The students need to learn first-hand how to be more efficient with their energy in order for them to truly understand the situation.

  • Ecological: The technology we introduce such as the microhydro system needs to have a minimal impact on the surrouding environment and habitat.

  • Compatibility with culture: The technology we introduce such as the microhydro system cannot be conflicting with the culture of San Pablo.

  • Communication: Information received from the community and information regarding their situation has been difficult and indirect to retrieve. More effective communication will be required to further progress the project.

San Pablo’s Efficiency/Technology Problem:

  • They are inefficient in their energy usage primarily in the following

    • heating their water
    • lighting
    • showers


If the people of San Pablo are going to move themselves they must first educate themselves on how to use their power in a more efficient way. It is not enough that we simply list off ways that they can conserve power. We must first develop a curriculum that explains the importance of energy efficiency in terms of how it is good for them and the world as a whole.

Guateca Curriculum

  • Curriculum to teach the locals:
    • The importance of being efficient with their power
      • Financially (ease tensions with power company)
      • Environmentally
    • How to be energy efficient
    • Power Assignment – Students will be given power meters to measure their household power consumption for a week and ultimately the cost of their usage. The students will then be assigned to measure their power consumption the next week with the goal of achieving the lowest power consumption using what they have learned so far in the proposed curriculum.
    • Micro-hydro Assignment
      • (See below)
    • Environmental Impact AssignmentThis is similar to the carbon footprint assignment our class has done, we want students to calculate their carbon footprint as is. Students can then recalculate what they predict their footprint will be if their electricity is completely provided by a micro-hydro system and with the implementation of efficient technologies. How would this affect CO2 emissions if all of Guatemala used sustainable electricity, or all of the world?
    • Financial Analysis Assignment – Our goal here is to teach students the cost-saving importance of switching to a self-sustaining electricity source. We want to show them how to do basic comparison analysis and to learn the basics of project investment.

Efficient Technology/Usage

  • Lights
    • turn off when not needed (on timers)
    • energy efficient light bulbs
      • Compact Fluorescent Light bulbs (CFLs)
      • Light Emitting Diodes (LED)
    • better windows
    • sky lights
  • Better stoves
  • Better insulation
  • More efficient showers.
    • After doing some research, we found that heating systems (such as electric water heaters) take up the most amount of electricity. A more efficient form of heating water, like the one Rory constructed using the heat from the flu of a stove. This is important because San Pablo has a restricted amount of electricity they can use at a time with the new micro hydro system. By eliminating the need to heat water with electricity, the people of San Pablo are much more likely to be able to keep under the limit of the micro hyrdo system.
  • Cut back during peak usage/distribute the usage more evenly throughout the day

San Pablo’s geographical position presents a great opportunity for a micro-hydro system to be effectively implemented. There are suitable rivers/streams nearby that could generate enough energy to provide the town with a significant amount of electricity.

The flow rate of the river during the wet season and dry season has been determined to be 200 L/sec and 80 L/sec respectively with a elevation drop of 150 meters.* Assuming a system efficiency of 50% of the proposed micro-hydro system, a lower-limit of 58.8 kW (kilowatts) of energy can theoretically be produced. This would amount to 65 kWh (kilowatt hours) per household per week.

Currently, the average household is consuming around 80 kWh per week. Reducing energy consumption by 15 kWh (18.75% reduction) may easily be achieved through the implementation of more sustainable energy practices as stated in the previous section.

*Numbers from Alterna


Estimated Micro Hydro Electricity Production

Alterna, an alternative energy provider located in Guatemala, can set up a 60 kW micro-hydro system to the village. Alterna has given the following price breakdown for the 60 kW system.

*Micro-hydro system images from Steve Crowe at AlternaAssumptions (from Alterna)

  • Wet Season Flow Rate: 200 L /secNueva_Alianza2.jpg
  • Dry Season Flow Rate: 80 L /sec
  • Elevation Change: 150 m
  • System Efficiency of 50%
  • 58.8 kw Production

Estimated Micro Hydro System Costs

  • Development Costs = $3,500/kw
  • Transmission Costs = $30,000
  • Total System Cost = $3,500(58.8 kw)+$30,000=$235,800



  • Down Payment = $100 per family
  • Interest Rate = 5%
  • Expected Annual Maintenance Costs = $10,000
  • Monthly Payment: $1,099.87
  • Monthly Payment Per Family: $8.09

The price of this system is very reasonable and the people of San Pablo could afford this system. The problem comes with the discrepancy between the amount of energy they are currently using and the amount of power the new system can produce. In order to be able to implement this system to the point of effectiveness, that being getting San Pablo completely off the grid, changes in the their behavior, as far as it depends on electricity, need to change. Our calculations, based on representative samples from San Pablo, show that the average home needs to reduce their power consumption by about 20 kWh a week.

Implementation/Dissemination Model

Guateca is a collaborative education program between Cal Poly [San Luis Obispo] and San Pablo students, faculty, and citizens in San Pablo, a village of 800 in the Guatemalan mountains”. Guateca will be used as our mode of dissemination. Through the series of educational problem sets, students will become acquainted with alternative energy solutions and the importance of efficient energy consumption.

Power Assignment:

The first step in reducing power consumption is education, that’s why Pete introduced this assignment (below) into Guateca; to have the students learn about electricity use in their own home and village, and learn what devices use what amount of power.

HW 4: Domestic Power Project, Nuclear, PSc-320 Schwartz Due Friday Aug 29 AT 9:00 AM. Please do this for every house someone in your group lives in. Do it in groups of 2 or 3.
1. San Pablo Load Curve (80 pts): Please answer the questions, but also put everything in a spreadsheet and include a printout. You have received a power measurement device. You plug it into the wall and plug any (EVERY) electrical device into it. It will read the power that this device is using at any moment. Some things like refrigerators and microwave ovens may cycle on and off, so you have to watch them for some time.

  1. Record present reading on the electrical meter outside your house. Mark the time and date that you take this reading. Do it again exactly 1 week later.
  2. You are to measure the power output of every electrical device that you can get your hands on (at least 10 devices). Measure the power when the device is on, and when it is “off”. If it is something you can turn up, like a stereo, measure it with loud and soft music. Some things cycle on and off like a refrigerator, so you may have to wait a while (or leave the door open) to get a measurement with it on.
  3. What do you observe when you measure the microwave oven on different power settings?
  4. Measure your laptop (or someone else’s) when the battery is low, when the battery is partially full, when the battery is full, when the battery is pulled out of the computer?
  5. For light bulbs in your house, read the wattage of each and record this amount. Then plug each light bulb into a lamp that you can plug into the Watt-Meter
  6. The electrical power into a device is (exactly) equal to the power the device gives off. We can estimate this power, which can take the form of radiated light, heat, sound, increased potential energy, etc. For each device, in the your Excel table, please make a note of what form(s) of energy is given off, in order of greatest amount of energy to lowest amount of energy.
  7. Make an estimate of what portion of time each device is being used.
  8. Predict the total electricity consumption in your home for a month, put answer in kWh.
  9. Create a table that has each hour of the day for each column (12 AM – 1 AM, 1 AM – 2 AM, etc.) followed by the average power used during that hour. This will be used to build a load curve for San Pablo just like our California Load Curve.
  10. Estimate what the monthly electrical bill should be if the price of electricity is $0.15 / kWh. Find the cost of electricity in San Pablo, and predict the monthly cost in Quetzales.
  11. How does your family’s Electricity use compare to the average Guatemalan (give ratio)? With the average earth human?
  12. Which measurements surprised you?
  13. What is the easiest way to lower your electrical consumption?:
  14. Through increased efficiency measures?
  15. Through conservation measures?

2. Measure the power output of an electrical shower. Do this by measuring the heat energy that the electrical device puts into the water over a period of time. Q = mcΔT. Does your answer equal the rated power printed on the showerhead? If not, how might you explain the difference?

3. Calculate the Buss Bar cost of coal-fired electricity. Do this problem on an Excel spreadsheet… you don’t have to do this on paper with a pencil. Calculate the cost of producing electricity from a coal facility. Let’s say you build a coal a 1 GW Coal-fired electrical facility for $1.50 per Watt (look it up to see how close I am) by borrowing money from the bank at an interest rate of 7% to be paid off over 30 years. You achieve an efficiency of 33%, and a duty cycle of 85%.

  1. What is the amount that you have to pay off each year to the bank for the mortgage on your loan?
  2. How much electrical energy do you generate each year?
  3. How much coal energy do you have to buy each year?
  4. How much money do you spend on coal each year (you will need to look up the cost of coal, and know the energy density of coal – which is different for the different kinds of coal)?
  5. Calculate the cost of producing electricity in $/kWh.

We conducted this assignment ourselves and found that it was very useful in serving its purpose as an educational tool (load the final presentation powerpoint below under Additional Information/Links to see our results). To proceed from here we decided that the best thing to do was not to change this assignment, but to add to it. The following assignment is designed to have the students calculate the feasibility of implementing a micro hydro system in their own village. This will allow them to discover for themselves the current problems in implementing the system and to find solutions to those problems.

Micro-hydro Assignment

  • 1) Calculate the amount of power an appropriate microhydro system would generate taking into account flow rates of local rivers and the change in elevation from intake to the turbine
  • 2) Calculate how much power each household can utilize in the respective seasons in Watts using the proposed microhydro system
      • a ) Determine the lower-limit and upper-limit of the amount of power produced taking into account the difference in seasonal flow rates
  • 3) Calculate the amount of kWh an average household can utilize in a week
  • 4) Compare this result to the data collected from the Power Meter Assignment
  • 5) If the collected data from the Power Meter Assignment is significantly higher than the results from step 3, discuss ways in which a household can lower their power consumption to meet this value.
  • 6) Using the discussed methods, try to reduce your household’s power consumption by 10 kWh

Grant Proposal Conclusion:

“Receiving this grant would enable us to bring a comprehensive energy curriculum to the people and students of San Pablo. It could also aid in the development of a micro-hydro system and the implementation of appropriate, efficient technologies. Their desire and need to separate themselves from the current energy grid continues to grow and may soon result in tragedy and fatality. The possibility of this has become all too real and actions need to be made sooner rather than later.

Real progress can be made throughout the community. San Pablo can become self-reliant and sustainable in their energy production/consumption with the fiscal aid of this grant. In turn, San Pablo can also act as a successful model for the neighboring communities, as it has already been. Eight years of not paying for electricity has ingrained certain bad habits into the village. This grant can act as a catalyst for change and development in a community that has the will to implement the use of alternative and efficient energy. “

*link to full grant proposal is linked below


Additional Information/Links:

Powerpoint Presentations:
San Pablo Project.ppt
San Pablo #2.ppt
Final_Presentation (4).ppt

Analyze your own power usage:
If you have PG&E, you can create and account online
and view reports on your power usage on an hour by
hour, or month by month basis here:

Grant Proposal: